1. Field of the Invention
The present invention relates generally to a printing apparatus. More specifically, the invention relates to a printing apparatus which can perform printing operation depending upon characteristics of a printing agent, such as an ink or so forth and components of the apparatus, such as a printing head and so forth to be employed in printing.
2. Description of the Related Art
In the recent years, owing to spreading of personal computers, wordprocessors, facsimiles and so forth in offices, various systems of printing apparatus have been developed as information outputting apparatus for these devices. Amongst these printing apparatus, an ink-jet type printing apparatus is suitable for personal use in the office or so forth for advantages of low printing noise, capability of high quality printing on various printing mediums, easiness of down-sizing and so forth. Among various ink-jet type printing apparatus, a construction, in which an ink-jet cartridge formed by integrating an ink tank storing an ink and a printing head converting an electric signal into a heat by a electrothermal transducer element and whereby causing film boiling in the ink for ejecting the ink by utilizing a pressure of bubble generated by boiling, is replaceably provided, is becomes a main current.
Such ink-jet cartridge permits shortening of an ink passage between the printing head and the ink tank. In this way, the ink-jet cartridge may lower production cost, and, as well, can reduce a consuming amount of the ink during suction recovery. In addition, when the ink in an amount to be used throughout the life of the printing head is stored in the ink tank, ink supply and maintenance of the printing head can be simultaneously done by replacement of the ink-jet cartridge by the user. Furthermore, the user may selectively use the ink-jet cartridges for color printing and monochrome printing. Such type of printing apparatus have been proposed.
Also, in view of significant expansion of the life of the printing head, there have been recently proposed printing apparatus which permit replacement of the printing head and the ink tank independently of each other.
In such printing apparatus, mainly for the purpose of improvement of printing quality, it have been becoming typical to preliminarily set a temperature management condition of the printing head and/or a head driving condition and so forth (these will be hereinafter generally referred to as xe2x80x9cprinting parameterxe2x80x9d) depending upon characteristics of a printing agent, such as the ink or so forth and apparatus components, such as the printing head and so forth.
One example of the printing parameter is a table data of temperature increase (rising) of the printing head to be used for detection of the temperature of the printing head. This table data is adapted to be used for arithmetically predicting variation of a head temperature on the basis of applied energy for the printing head. By controlling the energy to be applied on the basis of the predicted temperature, the temperature of the printing head can be controlled within a desired range, or ejection recovery process for the printing head can be controlled.
As one example of a method for predicting the head temperature, there is a method to perform calculation by adopting the behavior (increasing) of temperature of the printing head to a relatively precise physical formula of heat transmission. However, since the applied energy is sometimes varied depending upon the pattern to be printed, huge amount of process period and process capacity are required for performing arithmetic operation with adopting the temperature behavior to the physical formula set forth above.
Therefore, conventionally, the following method has been typically taken as an arithmetically predicting method of the head temperature. Namely, at first, the printing head which is constructed by assembling a plurality of components, is modeled as a composite body of a plurality of components having mutually different thermal time constant. Normally, the model is established with thermal time constant groups less than actual number of components by forming thermal time constant groups with approximately respective components to the group having the closest thermal time constant. Then, with respect to each modeled thermal time constant group, transition of temperature is calculated in discrete manner. The calculated values for respective thermal constant groups are accumulated to perform calculation of the temperature of the printing head. At this time, in order to reduce load on calculation of the temperature respect to each thermal time constant group, a table of data preliminarily calculated with respect to transition of temperature, is established in a form of two-dimensional matrix of a printing ratio (applied energy) per unit time for each of the thermal time constant groups and an elapsed time.
So-called open loop temperature control, in which temperature prediction as set forth above is performed, is advantageous in comparison with a closed-loop temperature control in which a temperature detection sensor is used, in response characteristics of detection of temperature, resistance against electrical noise and cost.
Another example of the printing parameter is data relating to an electric pulse for driving the printing head.
In general, the drive pulse (e.g. pulse of voltage) to be applied to the electrothermal transducing element in the ink-jet printing apparatus is set with mainly considering a physical property of the ink to be used, a heat generation amount per unit area at an ink contact surface of the electrothermal transducing element upon applying the pulse, and durability of the printing head against a stress in expansion and contraction due to heat.
On the other hand, in the ink-jet printing apparatus, as one of a method for realizing high printing quality, a construction for controlling the drive pulse to be applied depending upon the temperature of the printing head. Generally, this is because that when the temperature of the printing head, i.e. the temperature of the ink to be ejected, is varied, the ejection amount of the ink is varied according to temperature variation, and thus, if the drive pulse is fixed, the ejection amount is varied due to variation of the head temperature depending upon accumulation of heat during printing, or so forth to cause fluctuation of density of the printed image.
The setting data of the drive pulse and the control data of the drive pulse detecting upon the temperature as set forth above are preliminarily set and stored in a memory, such as ROM and so forth.
However, since the printing parameter is preliminarily set in production of the apparatus and so forth, as set forth above, the problems discussed hereinafter may be encountered.
The printing parameter, such as the head drive data and so forth, is set corresponding to the characteristics of the printing head and the printing ink upon putting the printing apparatus into market. Therefore, when superior quality of printing head and/or the printing ink which are the primary technology in the ink-jet printing apparatus, are developed through innovative activities and when such superior quality of printing head and/or the printing ink are applicable for the printing apparatus which have already been in the market, the table for predicting temperature and head drive data which are preliminarily set and stored in the existing printing apparatus cannot always be suitable for such newly developed printing head and/or the printing ink. Therefore, the user employing the prior marketed printing apparatus may not use the newly developed printing head and/or the printing ink at the optimal drive condition. In other words, such incompatibility of the printing parameter may be a constraint in application of the newly developed printing ink and/or the printing head and so forth in the printing apparatus having older specification.
In particular, in case of the printing apparatus which is replaceably use the printing head and the ink tank as set forth above, improvement of the quality for the printing head and so forth independently of others is easy. Therefore, the above-mentioned problem becomes significant.
As one of the solutions for the above-mentioned problem, it has been known a construction, in which a memory, such as a ROM is provided for each individual ink-jet cartridge and the drive condition and so forth is stored with respect to each of individual cartridge. According to such construction, it is allowed to drive the printing head in an optimal condition with respect to each individual ink jet cartridge, and the above-mentioned problem can be solved at least. Employing such ROM in the printing cartridge which is consumables, however, gives rise to increasing of the cost of the products. Therefore, the conventional printing apparatus has been desired to be improved in view of these points.
It is an object of the present invention to provide a printing apparatus which can appropriately set a printing parameter depending upon modification of specification of a printing ink and/or a printing head and so forth.
Another object of the present invention is to provide a printing apparatus which can perform open loop control for a temperature of the printing head without being affected by external disturbance, such as delay in response or noise, at low cost and with high precision and high speed, and can cope with version-up of consumables, such as the printing ink, the printing head and so forth, without an increase of the cost of the products.
A further object of the present invention is to provide a printing apparatus which can set a driving condition corresponding to version-up of the printing head to a main body of the printing apparatus.
In a first aspect of the present invention, there is provided a printing apparatus performing printing on a printing medium by using a printing head, comprising:
an input means for externally inputting a printing parameter to the printing apparatus, the printing parameter being determined depending upon characteristics of at least a part of elements and being used for control of operation of the printing apparatus; and
a control means for performing control for the operation using the printing parameter input by the input means.
In a second aspect of the present invention, there is provided a printing method for performing printing on a printing medium by using a printing head, comprising the steps of:
inputting a printing parameter, the printing parameter being determined depending upon characteristics of at least a part of elements and being used for control of operation of the printing; and
performing control for the operation using the printing parameter input by the step for inputting.
In a third aspect of the present invention, there is provided a method for arithmetically predicting a temperature of a printing head for predicting a temperature transition of the printing head employing an arithmetic prediction parameter, comprising the step of:
taking the arithmetic prediction parameter from out side of an apparatus employing the printing head.
In a fourth aspect of the present invention, there is provided a printing method for performing printing by applying a drive pulse to a printing element of a printing head on the basis of a driving parameter, comprising the step of:
taking at least a part of the driving parameter from out side of an apparatus employing the printing head.
In a fifth aspect of the present invention, there is provided a system comprising:
a printing apparatus performing printing on a printing medium by using of a printing head; including:
an input means for externally inputting a printing parameter to the printing apparatus, the printing parameter being determined depending upon characteristics of at least a part of elements and being used for control of operation of the printing apparatus; and
a control means for performing control for the operation using the printing parameter input by the input means; and
an external apparatus inputting the printing parameter through the input means.